He is one of the most famous contributors in the medical science. He first introduced the germ theory of diseases. This is regarded as the base of today’s microbiology. He found out some of the notion of the microbe and he could find out that the viruses were not detectable through microscope. Another important contribution of Pasteur is to protect harmful microbes in a way called “Pasteurization” where harmful microbes are destroyed by hitting the food. He is undoubtedly the most influential scientist in medical science.